It would be nice if we had the evidence for this. We don't. While we have a decent amount of evidence for the details of the cura annonae under and following Augustus, we have really very little information about how exactly it worked in the Republic. We know that C. Gracchus established a subsidy for public grain to be sold at a greatly reduced price in quantities of 5 modii per month--not enough to feed a family, necessitating the further purchase of grain at market prices. This grain seems to have been purchased from the provinces at a fixed price, although how that works exactly with provincial tribute, which was paid often in grain, is not clear. We know that the private grain trade continued, and made up the bulk of the grain supply to the city, but we're really not particularly well informed as to how it was affected by the state-subsidized grain. In the Principate there were strict controls over the ability of private sellers to manipulate the market, but such controls did not exist in the Republic.

We do not know how state grain was distributed in the Republic. After Augustus we have pretty good information, but the cura annonae changed completely under Augustus, and we cannot extrapolate that information backward. We do not know how state grain before 58, when it was still being sold for a reduced price, made it from the public granaries to market. Did the state commission particular people, presumably appointed by the aediles, to sell it? We have no evidence for such a thing. Did the state give it to private sellers to sell? Surely not, as that would affect the price, and it's hard to believe private sellers would limit the amount purchasable to 5 modii. We do not know how the state grain was distributed after 58, when the cost was abolished. It could not have been done the old way, whatever that was, because the changes introduced by the lex Clodia and then by Pompey, Caesar, and Augustus were profound. Was it distributed by tribal divisores, as largess was? There's no evidence. Was it, as Tatum thinks, distributed by collegia? Again, there's no evidence and the suggestion doesn't make a lot of sense. Distributed still by the aediles? Seems doubtful, the aediles rarely managed anything on that scale, and surely Pompey's cura annonae would have stepped on their toes? I think Tatum argues pretty effectively against the idea that the tribune himself was placed in charge of the cura annonae, through the appointment of Sex. Cloelius to wide-reaching powers approaching those of Pompey, but that argument's still out there. The distribution matters, because without the knowledge even of how public grain made it from the public granaries to the citizens' hands we don't have a lot to go on with regards to the market impact of the cura annonae.

We know, or think we know, that in 58-57 the abolition of the price of public grain had a significant impact on the economy. 57 began with a famine, although there's not really any reason to think that there were bad harvests. Artificial famine was hardly unknown, because private sellers frequently hoarded grain and artificially reduced the amount supplied to the market in order to protect themselves against bad harvests. Cicero claims that the lex Clodia ate up a fifth of the treasury. But even if Cicero is being strictly truthful and not making that up for rhetorical effect, that doesn't seem to have been so subsequently. Pompey's cura annonae was apparently at least thought to have solved the problem, even though Pompey really didn't do very much. Did the economy restabilize along a new model? Did the mere appointment of Pompey to the cura annonae cause, as it did following his appointment to the war against the pirates, private grain sellers to put their trust in the system, even though not really much ended up being changed? Were there real famines, in Italy for example, that were diverting public grain and putting additional strain on the treasury that looked like the lex Clodia was at fault? We don't know, although we do know that Cicero and everyone else stops complaining after the association of public grain is transferred from Clodius to Pompey. The political implication there, with respect to Cicero, is obvious enough.

We do know that Clodius seems to have anticipated the argument that the lex Clodia de frumentaria would be costly. Cato was dispatched to annex Cyprus, which provided a large increase to state revenues, again throwing Cicero's claim about the cost of the public grain into doubt. No further extreme measures were ever needed, however, to continue funding the cura annonae.

To a certain extent, what we can say with certainty is the systems that were not in place in the Republic. The Principate had complex legal restrictions placed on private retailers and on the private shipowners who hauled both public and private grain. These latter were also subsidized provided under the Principate, provided that they hauled a certain amount of public grain. Augustus seems to have understood the problem with the grain supply more clearly than those before him. The problem with the city's food supply was not the public grain, but the private grain trade that citizens relied on to feed their families. Augustan programs to oversee the private grain trade stabilized the market, preventing the massive fluctuations in price resulting from private panic and manipulation of the market. None of this existed in the Republic, during which attention was only paid to the state grain, not the grain supply as a whole. Financially, both markets had to exist alongside each other, which the Principate accomplished. Under the Republic the general lack of coherent "financial systems," even when we can identify clearly that they did or did not exist, gives the appearance more that the public grain was sort of shoehorned in than anything else